Madonna sent a special birthday shoutout to the Princess of Pop with a chilling cover of Britney Spears' 2004 smash hit "Toxic" for World AIDS Day.

On Friday (December 1), the "Burning Up" living legend posted an infrared video of her performing an acoustic rendition of the "Slumber Party" singer's unforgettable dance pop on social media to promote the organization's mission to raise awareness of the AIDS pandemic by paying respects to the many lives that were lost to the disease since 1988.

Madonna captioned her video clip, "Silence = Death. Song For World AIDS Day!....Song For World AIDS Day!” before wishing her pop star pal (who turned 36 today) a happy birthday.

Listen to the Queen of Pop's "Toxic" tribute to the birthday girl herself in the clip, below.